The present invention relates generally to the detection and ejection of foreign matter from crop harvesting machines and, more particularly, to a release mechanism operatively associated with a trip mechanism for an electronic stone detector to effect the release of a trap door for ejection of the foreign matter from the flow of crop being harvested.
Generally, crop harvesting machines, commonly referred to as combines, include a crop harvesting header mounted at the forward end thereof to initiate the crop harvesting process. Normally, the harvested crop is consolidated within the header and fed to a centrally located conveying mechanism within a feeder housing. From the feeder housing the harvested crop is fed to the combine base unit for further harvesting treatment.
It has been found to be desirable to eliminate non-crop foreign matter from the flow of harvested crop before it reaches the base unit for further harvesting treatment. Foreign matter, including stones, wood and other debris, can be harmful to the harvesting equipment normally housed within the base unit. Combines utilizing the rotary harvesting principal are particularly susceptible to damage from such non-crop foreign matter.
Accordingly, non-crop foreign matter detection devices, commonly referred to as stone traps, have been developed. One such mechanical detection device utilizes a pinch roller mounted a predetermined distance above a trap door in the feeder housing such that the flow of crop passes between the pinch roller and the trap door. Non-compressible matter, such as stones, entering the crop flow between the pinch roller and the trap door and having a height greater than the distance between the roller and the trap door, is forced downwardly against the trap door to force the trap door open and eject foreign matter. Electronic detection devices have also been developed for sensing the presence of such matter and emitting a signal receivable by an ejection mechanism to remove the foreign matter from the flow of crop.
It has been found to be desirable to provide a release mechanism to effect the unlatching of the trap door, whether the foreign matter was detected electronically or mechanically. A trip link, movable by an actuator to be engageable with a cam member affixed to the pinch roller and rotatable therewith, the cam member causing the trip link to engage the release mechanism and effect the unlatching of the trap door, was developed for operative association with the electronic stone detector. However, since the pinch roller and the cam member affixed thereto were positionally adjustable to vary the distance between the pinch roller and the trap door, it was found to be necessary to adjust the components of the release mechanism and the trip link to assure proper cooperation with the cam member to effect the unlatching of the trap door.